Another vote for letting your kid pick it out. Even then,
I would start very basic and build up from there.
My kid has dumbbells but mostly uses a pull-up bar for pull-ups, chin-ups, and core work vs using the weights. He gets bored with weights at home, so opts for the fun things on the bar or does pushups and other things that are apparently more entertaining. We got a very solid pull-up bar that screws into place in a doorframe. If I did it over, we'd get a standalone bar so he could do more -- but we have a small condo, not a large house!
We have a weight bench and he doesn't ever use it, but obviously everyone is different! Your kid might love it and use it every day
